A highly pathogenic strain of avian influenza has been confirmed in a commercial turkey flock in Minnesota, marking the first finding of the H5N2 virus in the Mississippi flyway, the Agriculture Department says. The same strain had previously been found in backyard and wild birds in Washington, Oregon and Idaho, all part of the Pacific flyway. A 6-mile quarantine area has been set up around the infected Pope County, Minn. farm, and birds in the region will be tested for the virus, according to the Minnesota Board of Animal Health. The remaining birds at the farm will be killed. Highly pathogenic influenza viruses can spread quickly from flock to flock. Minnesota is the largest producer of turkeys. The risk to people from the virus is considered low, and no human infections have been reported. But Minnesota health officials are working with employees at the infected farm to make sure they take the proper precautions, according to USDA's Animal and Plant Health Inspection Service. The birds were tested at a University of Minnesota laboratory because of an increase in deaths among the flock. The APHIS National Veterinary Services Laboratories in Ames, Iowa, subsequently confirmed the finding. The first sign of highly pathogenic influenza in poultry is sudden death. The turkey producer is working with the state board and APHIS on plans to euthanize the remaining birds, disposing of their carcasses, and disinfecting the facilities.